Single-sided cartridge guide mechanism

ABSTRACT

An electronic printed board assembly comprises a printed circuit board which employs printed circuit card connectors electrically connected to components mounted on the board. The printed circuit board includes board level guides with slots for receiving correspondingly shaped ridges disposed on outer, lower portions of printed circuit card-bearing cartridges. The guides are preferably provided on only one side for each cartridge to improve packaging density. The surface guides, together with the cartridge design, eliminate the need for physical contact with surrounding enclosures or cabinets.

BACKGROUND OF THE INVENTION

The present invention is generally directed to a system, method, andapparatus for packaging electronic circuit components. Moreparticularly, the present invention is directed to a system forelectronic component packaging which permits easy insertion and removalof fully populated circuit boards without having to remove printedcircuit cards which have already been inserted into the boards. Evenmore particularly, the present invention is directed to systems,methods, and devices which enhance the ability to package electroniccomponents in a dense manner while still being able to provide not onlyair cooling but which also provides an effective system forelectromagnetic interference (EMI) shielding.

It should be appreciated that not all of the features of the presentinvention need to be incorporated into a single device or system. Manyof the features found in the present invention may be employedindependently from one another. In general, the present invention seeksto solve a number of problems with respect to electronic circuitpackaging. In particular, it is desirable to employ printed circuitcards which can be easily inserted and removed from printed circuitboards without the removal of the board and without removal of anycabinet or enclosure surrounding the electronics package. In desiredembodiments of the present invention, therefore, it is found thatprinted circuit cards are capable of being “hot plugged” into a printedcircuit board.

Additionally, it is noted that, in preferred embodiments of the presentinvention, circuit components operate at relatively high frequencies. Athigher frequencies, problems associated with the propagation ofelectromagnetic interference become more significant. Accordingly, forthose situations in which higher frequency components are desired, thereis a correspondingly higher desire to employ electromagnetic shieldingsystems. Thus, there should be provided a mechanism for providing EMIshielding that is commensurate with the notions of hot pluggability. Inother words, the EMI shielding system should be compatible with thenotion that printed circuit cards are removed and inserted from printedcircuit boards which are themselves not pluggable.

Hot pluggable systems are shown in U.S. Pat. No. 6,062,894 issued May16, 2000, and assigned to the same assignee as the present invention.However, in the system described therein, there is a dependence on theexistence of an external cabinet to effect the vertical motion of theprinted circuit card into a corresponding mating socket on a printedcircuit board. The presence of physical contact between the mechanismfor insertion and removal and an enclosure which surrounds a printedcircuit board precludes the use of such devices in mechanisms for whichthe entire printed circuit board itself is removable.

It is also noted that the present discussion refers to printed circuitboards and printed circuit cards. As contemplated herein, the printedcircuit board is the larger component into which at least one printedcircuit card is inserted for purposes of electrical connection. Thepresent invention places no specific limits on either the size of aprinted circuit board or the size of a printed circuit card. In the mostgeneral situation, a circuit board is populated with a plurality ofprinted circuit cards. That is, the printed board has a number ofprinted circuit cards inserted therein. Accordingly, as used herein, theterms “printed circuit board” and “printed circuit card” are consideredto be relative terms. However, it is also noted that one of themotivating factors in the design of the present invention is the factthat printed circuit boards are, when fully populated, relatively heavyand possess one or more connectors at the edges thereof. These boardedge connectors typically possess a large number of electricalconnections to accommodate the correspondingly larger number ofelectrical connections that must be accommodated for a board which ispopulated with a number of printed circuit cards. The present inventorshave also contemplated a mechanism for insertion of the entire board ina tight space without the necessity of removing any of the printedcircuit cards. Accordingly, some of the specific situations contemplatedby the present inventors have also resulted in the inclusion ofmechanisms for insertion and removal of fully populated printed circuitboards.

Normally the circuit board, the mother board if you will, is consideredfixed and does not usually constitute a movable structure. Moreover,even in those circumstances where one might contemplate inserting orremoving a circuit board, one would normally not consider such anoperation without first removing the printed circuit cards from theboard. Because a typical printed circuit board is often populated with arelatively large number of printed circuit cards, the size and weight ofthe circuit board is typically relatively large. Thus, one is normallypresented with the problem of moving (in forward and reverse directions)a large, flat, relatively thin substrate. Particularly during insertionoperations, such a physical structure is likely to experience bendingand flexing motions typically referred to as “oil canning.” Accordingly,solutions to problems in the present art address this issue as well.

Accordingly, the present inventors are presented with the followingsometimes competing packaging problems: oil canning, dense and closepackaging, air cooling, electromagnetic interference shielding, hotpluggability, the desire to provide an easy to load cartridge forcarrying printed circuit cards, mechanisms requiring a mechanicaladvantage for insertion and removal of entire circuit boards, theremoval of fully populated boards and the insertion thereof, and meansto provide a cooperative EMI shielding arrangement in a system whichprovides circuit board guide mechanisms which do not require physicalcontact with a surrounding enclosure or cabinet.

SUMMARY OF THE INVENTION

In accordance with a preferred embodiment of the present invention, anumber of features are provided which together solve all of thecompeting problems indicated above. In particular, a significant aspectof the present invention is provision of a docking cartridge whichserves as a printed circuit card carrier and which is capable, in and ofitself, of inserting and removing electronic printed circuit cards.While the present invention is particularly suitable for theincorporation of printed circuit cards meeting the so-called PCI(Personal Computer Interface) Standard, the principles of the presentinvention are generally applicable to any printed circuit card having anedge connector which is insertable into a corresponding mating connectoron a printed circuit board. The docking cartridge of the presentinvention includes an actuating mechanism for card insertion which iscompletely self contained and which does not rely upon any physicalcontact with an enclosure or cabinet. Rather, the docking cartridge ofthe present invention interacts with a single-sided cartridge guidemechanism which is provided at the printed circuit board level.Moreover, the docking cartridge of the present invention is providedwith an easy load mechanism for the printed circuit card. In particular,the docking cartridge is provided with a front bezel which alsoconstitutes part of an EMI shield mechanism and which is also pivotablewith respect to a top cartridge wall structure. The top cartridge memberis slidably disposed with respect to a circuit card carrier whichcontains corner clips and slidable adjustable mechanisms as shown in theaforementioned U.S. Pat. No. 6,062,894. The top member is thus slidablyattached to a moveable carrier which moves the printed circuit board upand down so as to provide insertion and removal of the circuit boardwith respect to mating electrical connectors on the printed circuitboard.

A front bezel of the docking cartridge is also provided with a mechanismfor ensuring EMI shielding during the entire insertion and removalprocess. In particular, desirable circuit boards for use in connectionwith the present invention include a front EMI shield plate which haselectrical contact with the front docking cartridge bezel. Inparticular, such desirable printed circuit cards having this plate alsoinclude, on the bottom of this shield plate, a tab portion which engagesa flexible EMI shield strip which is disposed on an electricallyconductive stiffener which provides protection against theaforementioned oil-canning effect and which furthermore provides its owndegree of EMI shielding for board level circuits and components. The EMIshield strip used in the present invention possesses a geometricstructure which renders it readily capable of being fabricated instamping and forming operations. This EMI strip is disposed so that itincludes slotted opening portions which engage edges of apertures foundin parallel rows in the stiffener. The strip engages these apertures inone row and includes a flexible portion which extends into the openingin a parallel row of stiffener apertures. Thus, in accordance with thepresent invention, as the printed circuit is inserted into the printedcircuit boards so as to make electrical contact with circuits on theboard, there is also provided a continuous EMI shield as the tab on theprinted circuit card engages a flexible tab portion on the EMI stripwhich is in electrical contact with the conductive stiffener.

One of the other significant problems addressed by the present inventionis the fact that a fully populated circuit board is relatively heavy andtypically possesses a large number of electrical circuit contacts thusincreasing the force needed to provide proper electrical connection. Themechanism for providing this force should not be significantly large norshould it consume significant amounts of space. That is to say, themechanism for inserting and removing the circuit board should be compactand consistent with the compact and dense packaging notions of thepresent invention. Furthermore, this mechanism should be compatible withthe other structures provided herein, notably, the stiffener and the EMIshielding system.

The present invention incorporates two principle aspects. A firststructural component utilizes an independent, self-contained cartridgefor containing printed circuit cards intended for insertion into andremoval from tight spaces. A second aspect of the present inventionincludes the structure of a printed circuit board which is usable inconjunction with the aforementioned cartridges. Furthermore, thecartridge and board system of the present invention cooperativelyinteract to provide EMI shielding mechanisms not only compatible withthe easy insertion and removal of circuit cards, but which also providea cooperative mechanism for the insertion and removal of an entirecircuit board in its fully populated state, that is, with all printedcircuit cards inserted and connected.

With respect to the first aspect of the present invention which relatesto the cartridge for protecting, transporting, inserting, and theremoval of printed circuit cards, it is noted that this cartridgeincludes three main components: a front bezel, a top cartridge wallmember, and a movable carrier which is upwardly and downwardly movablewith respect to the bezel and the top cartridge wall. The cartridge alsoincludes a lever actuated mechanism attached to the top of the bezelwhich provides sufficient force for card insertion. The lever actuatedmechanism of the cartridge is disposed in such a way as to provide bothupward and downward forces to the movable carrier at a point along thecarrier which is appropriate for both short and long printed circuitcards. The cartridge of the present invention also includes a sidecover. In preferred embodiments of the present invention, the bezel ismetal and is in continuous electrical contact with an EMI shield platefound on certain printed circuit cards which are desirably useful inconjunction with preferred embodiments of the present inventionparticularly when they operate at relatively high frequencies. Theseshield plates preferably include a lower tab portion which extendsthrough an opening in the bottom of the front bezel and which engages anEMI shield spring which thus allows it to be electrically connected witha conductive stiffener affixed to the printed circuit board.

With respect to the second aspect of the present invention which relatesto the printed circuit board itself, the board is provided with anelectrically conductive shield and stiffener as mentioned above withrespect to the incorporation of the tab and spring structures.Furthermore, printed circuit boards of the present invention include anonconductive base member which is disposed on a side of the printedcircuit board opposite the stiffener. This base support structureprovides additional resistance to “oil canning” effects that can occurparticularly in larger printed circuit board structures. The printedcircuit board also includes special guides disposed at the printedcircuit board level. These guides engage ridges disposed on side wallcovers for the printed circuit card cartridges, as described above. Aparticular feature of the cartridges also includes a mechanism forinterlocking adjacent cartridges. Accordingly, a desirable aspect of thepresent invention is the fact that the special guides employed herein donot require slot and ridge structures to be present on both sides of theinserted cartridge. This is significant in the present invention sincethis feature permits cards to be made thinner and accordingly increasesthe overall packaging density which, as described above, is a highlydesirable aspect of the present invention.

The stiffener employed in conjunction with the printed circuit boardincludes a front row of parallel slots which are spaced to receive anEMI spring shield structure which cooperates with the cartridgestructure to provide a continuous EMI shield. Additionally, the presentinvention also includes a force-producing mechanism which is capable ofproviding a significant mechanical advantage for insertion and removalof the printed circuit board itself, even when requiring all of theboard edge connectors to be mated with corresponding off-boardconnectors. In preferred embodiments of the present invention, theinsertion and removal mechanism for the printed circuit board includes atoothed arm which engages a wrench-activated pinion gear which isaffixed to the above-mentioned stiffener at the front or leading edge ofthe printed circuit board. The toothed arm is pivotally connected toforce-producing arms which include pins which ride in slots in the basestructure which supports the printed circuit board from below. As thepinion gear is rotated, the combination of the toothed arm and theforce-providing levers changes to and from a “T” and “Y” shape. Thus, asthe pinion gear is rotated, the lever arms move in what is bestdescribed as a “backstroke” motion. These levers push against cabinet orenclosure pins and, in doing so, cause the insertion or removal of thecircuit board, in its entirety, into or out of a mating electricalconnector.

The cartridge of the present invention is also constructed in such amanner so as to employ components which are pivotally connected so as toenable easy insertion of printed circuit cards having variousdimensions. In effect, the maximum size of a card employed in thepresent invention is thus determined by the height of the bezel and thelength of the cartridge top.

Accordingly, it is an object of the present invention to provide asystem for packaging electronic circuit components in tight spaces.

It is also an object of the present invention to provide an apparatusfor inserting and removing printed circuit cards in tight quarters.

It is a still further object of the present invention to provide acartridge which is capable of transporting, protecting, inserting, andremoving printed circuit cards in a self-contained manner.

It is also an object of the present invention to provide mechanismswhich support hot pluggability of electronic circuit cards and boards.

It is a still further object of the present invention to provide amechanism which permits insertion and removal of fully populatedelectronic circuit boards.

It is also an object of the present invention to provide a cartridge,for containing printed circuit cards, which is easily loadable.

It is furthermore an object of the present invention to provide a systemin which continuous EMI shielding is provided between an easilyremovable printed circuit cartridge and a printed circuit board.

It is yet another object of the present invention to provide a cartridgefor printed circuit cards which is readily adapted to hold cards ofvarying sizes.

It is yet another object of the present invention to provide a system ofinterlocked printed circuit card cartridges and a supporting printedcircuit board.

It is yet another object of the present invention to provide a mechanismby which an entire fully populated printed circuit board is readilyinserted into and removed from the system in which it is electricallyconnected.

It is also an object of the present invention to provide a printedcircuit cartridge card carrying mechanism which is compatible with aircooling of the components contained on the card.

It is a still further object of the present invention to provide aprinted circuit board which is still nonetheless compatible with theincorporation of ancillary circuit components such as capacitors,resistors, heat sinks, and the like which extend upward from the printedcircuit board.

It is a yet another object of the present invention to provide an EMIshield spring structure which is operative as a mechanism for providingelectrical connections and EMI shielding continuity between a printedcircuit card and an EMI shield structure disposed on a printed circuitboard to which the card is also separately electrically connected.

It is a further object of the present invention to provide a guidemechanism on a printed circuit board for cartridge insertion so as toconsume only a small space in the side-to-side direction, between loadedcartridges.

Lastly, but not limited hereto, it is an object of the present inventionto provide an integrated printed circuit card cartridge and printedcircuit board mechanism which provide compactness, air-coolingcapabilities, EMI shielding, hot pluggability, and mechanical forceadvantages both for the insertion and removal of printed circuit cardsand the insertion and removal of fully populated printed circuit boards.

The recitation herein of a list of desirable objects which are met byvarious embodiments of the present invention is not meant to imply orsuggest that any or all of these objects are present as essentialfeatures, either individually or collectively, in the most generalembodiment of the present invention or in any of its more specificembodiments.

DESCRIPTION OF THE DRAWINGS

The subject matter which is regarded as the invention is particularlypointed out and distinctly claimed in the concluding portion of thespecification. The invention, however, both as to organization andmethod of practice, together with the further objects and advantagesthereof, may best be understood by reference to the followingdescription taken in connection with the accompanying drawings in which:

FIG. 1A is an isometric view illustrating a cartridge in accordance withthe present invention;

FIG. 1B is a side elevation view of the cartridge shown in FIG. 1A;

FIG. 2 is a side elevation view of the cartridge shown in FIG. 1B exceptwith the cover removed so as to provide a view of some of the interiorcomponents;

FIG. 3A is a side elevation view illustrating a preferred levermechanism for card insertion and removal and more particularlyillustrating lever arm positions when a card is fully inserted;

FIG. 3B is a view similar to that shown in FIG. 3A except that the leverpositions shown are indicated when a card is a in the fully removedposition;

FIG. 4 is an isometric view illustrating the combination of a topcartridge wall member together with a movable card-carrying mechanism;

FIGS. 5A through 5I illustrate a sequence of operations for the loadingof a printed circuit card into the cartridge of the present invention;

FIG. 6 is an isometric view illustrating a cartridge of the presentinvention inserted into a single slot on a printed circuit board whichalso conforms to the requirements of the present invention;

FIG. 7 is an isometric view similar to FIG. 6 but more particularlyillustrating the entire printed circuit board with a single cartridgeinstalled;

FIG. 8 is an isometric view illustrating a detailed portion of a printedcircuit board in accordance with the present invention and particularlyillustrating a guide system as preferably employed herein;

FIG. 9 is an isometric view illustrating the bottom of a printed circuitboard in accordance with the present invention and more particularlyillustrating a preferable mechanism for circuit board insertion andremoval;

FIG. 10 is an isometric view illustrating (in a detailed close up) aportion of the preferable board insertion and removal mechanism as shownin FIG. 9;

FIG. 11 is an isometric view illustrating the actuation mechanism forthe drive arm shown in FIG. 9;

FIG. 12A is a side elevation, cross-sectional view illustrating the EMIshield system of the present invention particularly with respect to thecooperation between printed circuit board shield plates, cartridgebezels, EMI shield springs, and conductive stiffener structures;

FIG. 12B is a simplified view of the system shown in FIG. 12A providedto more particularly indicate movement of the components;

FIG. 13A is a top view of the EMI shield spring employed in conjunctionwith the EMI system of the present invention; and

FIG. 13B is a side elevation view of the spring shown in FIG. 13A.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1A illustrates an isometric view of a preferred embodiment of thepresent invention. In particular, FIG. 1A illustrates cartridge 100which contains printed circuit card 200 (visible in FIG. 2). Cartridge100 includes front wall or bezel 130 which preferably comprises metal.Bezel 130 is pivotally attached to top wall member 120 of cartridge 100.Side cover 110 is attached to bezel 130 at points 137 and 138. Notably,side wall cover 110 includes ridge portion 111 extending along a bottomportion of wall 110. Additionally, as an additional major component,cartridge 100 includes actuating lever arm 141 which is used to insertand remove printed circuit card 200 from printed circuit boards intowhich cartridge 100 is inserted. Additional appreciation of theoperation of cartridge 100 is discernible from the side elevation viewshown in FIG. 1B which particularly illustrates pivot point 144 foractuating lever arm 141. By operation of lever arm 141, an internalmechanism (not visible in FIG. 1A or 1B) urges printed circuit card 200having edge connector 201 into corresponding mating connectors (311 inFIGS. 6, 7, and 8) on circuit board 300 whose construction is moreparticularly described below and which cooperatively interacts withcartridge 100 in several ways.

Top wall member 120 preferably comprises a polymeric material whichexhibits sufficient stiffness to support the operation of the lever armmechanism which is included in preferred embodiments of the presentinvention. Top wall member 120 also preferably includes apertures 121near the front of the cartridge and aperture 122 near the read ofcartridge 100 for the passage of cooling air for those situations whereair cooling is desirable. Top wall member 120 is preferably formed toexhibit a generally U-shaped cross-section as a major portion of itsstructure.

Side wall 110 also preferably comprises a polymeric material which issubstantially flat and is attachable to top wall 120 along the top edgeof wall 110 using any convenient attachment means such as screws 176,177, and 178 as shown in FIG. 5H which is more particularly consideredbelow. Significantly for the present invention, side wall 110 includes araised portion or ridge 111 which extends along a bottom portion of sidewall 110. Ridge 111 may possess any convenient cross-section, however, asmooth-rounded cross-section is shown. The main feature of ridge 111 isthat it possesses a cross-section which matches the cross-section ofslots 351 provided in guides 350 (see FIG. 10) affixed to printedcircuit board 300.

Front wall portion (or bezel) 130 is pivotally attached to top wallmember 120 at pivot point 137. Front wall 130 also preferably includesmounting bracket 149 to which is attached actuating pivot arm 141 whichis used as an external drive mechanism for insertion and removal of aprinted circuit card 200 into a printed circuit board connector 311.Front wall 130 preferably comprises a conductive material whenever it isdesired to provide electromagnetic interference shielding. However, inthose circumstances in which EMI shielding is not essential or desired,front wall 130 may comprise a polymeric material or other nonconductivematerial. Front wall 130 also preferably includes an opening in thefront thereof through which printed circuit board shield plate 202 isvisible. In other applications of the present invention, front wall 130is provided with an opening in the front thereof so that access may beprovided to various pluggable connectors that may be found on the frontedge of a printed circuit card. Such printed circuit board connectorsare disposed through the opening in front wall 130 and may includetelephone line RJ-11 type connectors and the like. Front wall 130 alsopreferably includes one or more openings for the inclusion of lightguides 132 which are optionally provided so that light indicators, suchas LEDs found on the leading edge of printed circuit board 300, may beviewed from external positions.

It is noted that the present invention incorporates a number of featuresthat have been provided for specific purposes. For example, in thoseapplications in which relatively high power levels are generated by anenclosed printed circuit card, it is desirable to provide top wall 120with apertures (121 and 122) such as those shown in FIG. 1A. However, ifpower dissipation is not a concern, such apertures do not have to bepresent. Likewise for those situations in which connector access toprinted circuit card components is not necessary, front wall 130 doesnot have to be provided with an opening. In a similar fashion, in thosesituation in which electromagnetic interference is not an issue, frontwall 130 may comprise materials which are not electrically conductive.In general, the nonconductive portions of cartridges manufactured inaccordance with the present invention are preferably formed in polymericmolding operations.

The cartridge of the present invention is particularly useful in thosesituations in which it is desirable to have a relatively high componentpackaging density. Accordingly, it is desirable that cartridge 100 beshaped in as a thin a package as possible so that as many cartridges aspossible may be disposed in adjacent positions. Accordingly, inpreferred embodiments of the present invention, only cover 110 on oneside is provided. In such embodiments, there is only one ridge 111 whichengages mating guides 350 on printed circuit board 300. The lack ofnecessity for providing a ridge and cover on the opposite side ofcartridge 100 is eliminated. By eliminating this structure, cartridge100 may thus be made thinner. In yet another variation of the presentinvention, in those circumstances in which a plurality of cartridges areinserted in adjacent positions, as is preferred in the presentinvention, cartridge 100 is provided with interlocking mating members112 and 113 (see FIG. 6) which serve to slidably interlock adjacentcartridges. This further contributes to the strength and rigidity of theentire structure. This interlocking mechanism also contributes to thelack of a need for cover such as 110 to be provided on both sides ofcartridge 100.

FIG. 2 is a side elevation view similar to that shown in FIG. 1B exceptthat cover 110 is removed so as to more particularly show and illustratethe internal components and the inclusion of cartridge 100. Inparticular, FIG. 2 shows printed circuit card 200 with its edgeconnector 201 affixed in position with respect to carrier 150. Carrier150 is a movable portion of the present invention, and it is the part ofthe mechanism shown in FIG. 4 as described below which provides adescription of a preferred mechanism for carrier 150. FIG. 2 alsoillustrates that in those embodiments of the present invention in whichair circulation is a desired factor, front wall 130 also preferablyincludes a plurality of apertures 131 which also facilitate the passageof cooling air. FIG. 2 also illustrates the fact that front wall 130also preferably includes aperture 133 on the bottom thereof (see alsoFIGS. 12A and 12B) which provides an exiting path for tab portion 203 ofEMI shield plate 202 (see FIG. 12A) which serves as part of aninterconnnected EMI shield system. The remaining portion of FIG. 2serves to particularly indicate the preferred system of linked leverarms which are employed to effect the desired motion of carrier 150 andprinted circuit card 200. The action and operation of this levermechanism is more particularly illustrated in FIGS. 3A and 3B.

A preferred system of pivoting arms for moving carrier 150 is seen inFIGS. 3A and 3B. In particular, it is noted that pivot points 144 and147 are fixed. In particular, pivot point 144 is preferably fixed inbracket 149 which is affixed to a point on front wall 130 at the topthereof as shown. Likewise, pivot point 147 is affixed on top wall 120.In preferred embodiments of the present invention, top wall 120comprises a polymeric material having a substantially U-shapedcross-section. As such, this provides a mechanism for extending apin-like pivoting mechanism across the U-shaped channel. Thus, mostsignificantly for the present invention, it is seen that the preferredleverage mechanism includes pivot points 144 and 147 which are fixed tofront wall 130 and top wall 120, respectively. The preferred leveringmechanism includes external actuating arm 141, as shown. Second arm 143extends from fixed pivot point 147. Connecting arm 142 linking externalarm 141 with second arm 143 is also shown. Arm 141 and arm 142 arelinked at pivot point 146. Arm 142 and arm 143 are linked at pivot point145. Also notably for the present invention, at pivot point 145 there isprovided a pin which preferably rides in a horizontal slot provided incarrier 150. The motion of the pin in the slot is the mechanismpreferably employed for imparting upward and downward motion to carrier150.

It is noted that FIG. 3A illustrates the position of the various armsemployed in preferred embodiments of the present invention when printedcircuit card 200 is fully inserted into board connector 311. Likewise,FIG. 3B illustrates the position of a desired leveraging mechanism whencard 200 is fully removed from board 300. It is also noted that sincefront wall 130 is pivotally connected to top wall 120 at pivot point137, the mechanism shown in FIGS. 3A and 3B is particularly useful inthat it permits the pivoting operation to occur by providing a longerdistance between pivot point 147 and pivot point 146, thus permittingextension of the configuration of the arms used for insertion andremoval during bezel pivoting.

FIG. 4 illustrates the fact that carrier 150 preferably comprises twoprincipal components: tail stock component 150 a which possesses acertain degree of flexibility (as is discussed more particularly belowin reference to FIG. 5B) together with flat wall member portion 150 b.Carrier wall portion 150 b (also referred to herein using referencenumeral 152) includes guide portions 153. Guide structures 153preferably include tongue and groove-like structures which serve toguide carrier 150 in a more uniform vertical motion with respect to topwall 120. FIG. 4 also illustrates adjusting bracket 151 which includes atop portion (not visible) which rides in a toothed slot along tail stock150 a and includes a ratchetting pawl together with a release mechanismsuch as that shown in the above-referenced patent issued in the name ofone of the inventors herein. Adjusting bracket 151 therefore provides amechanism for holding various sizes of printed circuit cards in carriermechanism 150.

Attention is now directed to the sequence shown in FIGS. 5A-5I. Thissequence illustrates the easy loading aspects of the present inventionwith respect to the placement of printed circuit cards therein. A partslist for a cartridge in accordance with the present invention includes:(1) bezel and linkage subassembly (front wall 130, top wall 120, linkagemechanism 141-149, and carrier 150); (2) cover 110, clip 154; (3) shortcard arm 155′; (4) long card arm 155″; and (5) eight screws (171-178).

In preferred embodiments of the present invention, printed circuit card200 to be inserted is a standard PCI (Personal Computer Interface) card.However, the present invention is not limited to the utilization ofthese specific printed circuit cards.

The process for inserting card 200 into cartridge 100 of the presentinvention begins with a consideration of FIG. 5A. Printed circuit card200 is oriented as shown by loading the upper front corner of card 200into clip 154 and rotating card 200 so that it engages its heel portionwith slot 156. This operation is done for both short and for longprinted circuit cards. To accommodate cards which are short in height,clip 154 is slid down until the card is held securely at clip 154 and atheel 156 together. For a detailed description of appropriate slidingmechanisms for carrying out this operation, attention is directed to theabove-mentioned patent. The operation shown in FIG. 5A is performed withfront wall or bezel portion 130 rotated out of the way, as shown.

Next, as illustrated in FIG. 5B, tail stock portion 150 a of carrier 150is bent down (150 a′) to allow for either short card arm 155′ or longcard arm 155″ to be attached to carrier 150. In particular, carrier 150with tail stock portion 150 a is shown as 150 a′ as being bent down inFIG. 5B. Arms 155′ and 155″ (not both present at the same time) areprovided for slideable adjustment along tail stock 150 a of carrier 150.In particular, in preferred embodiments of the present invention, thesearms slide in a ratchetting toothed strip and are provided withreleasable pawl mechanisms for snugging up against inserted printedcircuit card 200. Again, attention is directed to the above-referencedpatent which is incorporated herein by reference. To position arm 155′and 155″ onto a card edge, the arm is slid horizontally. When the arm issquared to the card edge, the arms are pressed against the edge so as toengage clip or heel portions found on the bottoms of short or long cardarms 155′ or 155″.

FIG. 5C illustrates the fact that front wall or bezel 130 may also betemporarily removed from top wall 120 to accommodate passing tab 203 onshield plate 202 of printed circuit card 200 through aperture 133provided for that purpose in the front of bezel 130. FIG. 5C alsoillustrates the relative positions of adjusting arms 155′ and 155″(short card and long card positions, respectively).

FIG. 5D illustrates several additional features of the present inventionand further aspects of assembly. In particular, FIG. 5D illustrates thepresence of brace 136 which extends from a bottom portion of front wall130 in a substantially diagonal direction so as to be affixable to topwall 120 at point somewhat distal from the top portion of front wall130. Bracket 136 preferably comprises metal. It is attached to frontwall member 130 by any convenient means particularly including spotwelding. Bracket 136 provides additional rigidity which is found to beat least somewhat desirable when polymeric components are employed.

Additionally, FIG. 5D illustrates the presence of notch 139 in the sideof front wall member 130. Notch 139 is provided to permit easy passageof clip or heel 156 as front wall 130 is reattached to the assemblyduring loading operations for printed circuit cards. A more detailedview of this notch is provided in FIG. 5E.

Next is considered the illustration shown in FIG. 5F. FIG. 5Fillustrates yet another aspect of the present invention. In particular,FIG. 5F illustrates the relationship between top wall member 120, frontwall or bezel 130, and moving carrier 150 which includes tail stockportion 150 a and flat plate portion 150 b. In particular, FIG. 5Fillustrates the presence of brace 136 which extends from bezel 130 totop wall member 120 to which it is ultimately attached via two screws171 and 172 (see FIG. 5G). Since one of the objects of the invention isto provide as thin a profile as possible, while still preservingstructural rigidity, it is seen that carrier plate portion 150 b alsopreferably includes recess 157. The presence of recess 157 permits brace136 to be mounted in corresponding recess 129 in top wall channelsupport 120 using screws 171 and 172 as shown in FIG. 5G. Additionally,it is seen that top wall 120 and movable carrier 150 both include matingslidable portions 153 which provide improved guidance to more readilyensure vertical motion as lever 141 is actuated. Tongue and groovestructures are employed to provide suitably mated sliding portions. Itis also seen in FIG. 5F and in FIG. 5G that front wall or bezel 130includes notch 139 which is provided for ease of assembly and, inparticular, for ease in passage of clip 156 (see FIG. 5A).

In addition to the features shown above, it is seen that FIG. 5Gindicates the presence and utilization of adjustable arm 155′. Inparticular, the particular form of the adjustable arm shown in FIG. 5Gis that which is used to support short printed circuit cards.Additionally, it is seen that FIG. 5G illustrates the presence of tab204 which is preferably present on the top of EMI shield plate 202 whichis attached to printed circuit card 200 (see also FIGS. 5H and 5I). Inparticular, this tab preferably includes stamped or pressed prongs whichslide against the interior front wall portion of bezel 130 to providecontinuous electrical contact for purposes of providing continuous EMIshielding as lever 141 is actuated to move carrier 150 and board 200into position. It is also noted that, as this motion takes place due tothe actuation of lever 141, EMI shield plate 202 also moves downward soas to move tab 203 through opening 133 in bezel 130 (see FIG. 12B).

FIG. 5H illustrates a final assembly operation for a cartridge inaccordance with the present invention. In particular, it is seen thatcover 110 is slid into position and is fastened to top wall member 120using screws 176, 177, and 178, as shown. Lastly, front wall member 130is pivoted into final position and affixed to the assembly via screws174 and 175, as shown. The completed assembly is shown in FIG. 5I inisometric view.

Having described cartridges for carrying printed circuit cards,attention is now directed to the printed circuit board intended for usein conjunction with the cartridges of the present invention. Inparticular, FIG. 6 illustrates cartridge 100 fully inserted into printedcircuit board 300. In particular, it is noted that ridge 111 on cover110 slidably engages grooves or slots 351 in guides 350 which areaffixed to printed circuit board 300 through openings in stiffener 330.It is also noted that cartridge 100 preferably includes interlockingmechanisms 112 and 113. If a cartridge in accordance with the presentinvention were to be inserted in the slot just to the right of theoccupied slot in FIG. 6, its mating interlocking portion 113 wouldengage the corresponding mating interlocking portion 112 on thecartridge that is already shown. In this fashion when a plurality ofcartridges are inserted into a printed circuit board in accordance withthe present invention, there is formed an interlocking structure whichprovides enhanced strength, rigidity, and alignment characteristics.

FIG. 6 also illustrates the presence of a parallel row of apertures 331and 332 present in stiffener 330. These apertures accommodate the easyinsertion of EMI spring shield member 500 which is more particularlydescribed below (see FIGS. 13A and 13B). It is EMI shield spring 500which is engaged by tab portion 203 of EMI shield plate 202. Tab 203 isdeployed downwardly through opening 133 in bezel 130 to providecontinuous EMI shielding between card 200 and stiffener 330 whichpreferably comprises a conductive material such as metal when employedfor EMI shielding purposes.

Attention is next directed to the apparatus shown in FIG. 7. FIG. 7illustrates a number of the cooperating subsystems of the presentinvention. As with FIG. 6, it illustrates the cooperative interactionbetween cartridge 100 and printed circuit board 300 particularly withrespect to guides 350 present on board 300. Guides 350 also includeoptional alignment tabs 353 which serve as helpful guides duringcartridge insertion. In operation of the systems of the presentinvention, cartridge 100 is aligned with slots or grooves 351 (see FIG.8) in guides 350 and is inserted so as to occupy the position as shownin FIG. 7. At this point, lever arm 141 is actuated, preferably by alifting motion, which causes internally disposed carrier 150 to movedownward and to thereby insert card edge connector 201 intocorresponding printed circuit board connector 311. During actuation oflever arm 141, plate 202 with tab 203 is moved likewise downward so thattab 203 makes contact with EMI spring shield 500 which is already incontact with stiffener 330.

FIG. 7 also shows the preferable positioning for board insertion andremoval mechanism 400, or at least so much of that system as is visiblein FIG. 7. Additional aspects of board removal system 400 are moreparticularly described below. However, spur gear 411 and toothed arm 420(see FIG. 11) are nonetheless visible in FIG. 7.

FIG. 7 also indicates the inclusion of rear board edge connector 340disposed on the back edge of board 300. Also discernible in FIG. 7 isthe preferred structure of the present invention in terms of the printedcircuit board assembly itself. In particular, it is seen that board 300includes insulative base 320, printed circuit subboard 310, andstiffener 330. Stiffener 330 preferably comprises metal when employedfor EMI shielding purposes. However, in those embodiments of the presentinvention in which EMI shielding is not a factor, nonconductivematerials may be employed in the fabrication of stiffener 330. However,in preferred embodiments of the present invention stiffener 330preferably comprises a single stamped and formed sheet of metal.

As an additional observation with respect to FIG. 7, it is seen that, asis often the case with printed circuit board structures, certain circuitcomponents extend upwards from its surface. Accordingly, it is seen thatstiffener 330 may include selective apertures therein for the passage ofcomponents, such as capacitors 342 and/or heat sinks 341. Those skilledin the electronic arts will readily appreciate that other components maybe employed and may be positioned in different places with respect tostiffener 330.

FIG. 8 provides a more detailed view of some of the structures seen inFIG. 7. In particular, it is seen that circuit board connectors 311 aredisposed between rows of board level guides 350. In preferredembodiments of the present invention, guides 350 are formed from anintegral polymeric structure as is readily fabricated in a moldingoperation.

Attention is next directed to the description of the mechanism employedin the present invention for the insertion and removal of entire circuitboard 300 together with any cartridges 100 which may be inserted intoand connected with the board. Preferred embodiments of this mechanisminclude rigid driving arm 420 with toothed portion 419 which is drivenby spur gear 411 (see FIG. 11) which is affixed to plate 412 which inturn is attached to a formed portion of stiffener 330 (seen in greaterdetail in FIG. 11). Spur gear 411 preferably includes central hexagonalopening 413 for the insertion of an Allen wrench which causes rotationof gear 411 which moves drive arm 420 inwardly and outwardly in arecessed groove portion of base support member 320. There is preferablyprovided at least one lever arm attached to drive arm 420. In preferredembodiments of the present invention, two lever arms are provided. Theselever arms, 421 a and 421 b, are seen in FIGS. 9 and 10. Lever arms 421a and 421 b are pivotally attached to drive arm 420 at pin or rivet 422.Lever arms 421 a and 421 b also include pins 423 a and 423 brespectively as best seen in FIG. 10. These pins ride in slots 360 a and360 b respectively formed in base support member 320.

In what is best as described as a “back stroke motion,” as drive arm 420is driven inwardly, drive arm 420 together with lever arms 421 a and 421b change configuration from a “Y” configuration as seen in FIG. 10 to a“T” configuration as illustrated in FIG. 9. As the configuration ofthese arms changes, edges of arms 421 a and 421 b push against pinsfound on the enclosure or frame into which the board is inserted. Thesepins are located externally to the printed circuit board shown but arepresent at corresponding positions 430 a and 430 b on circuit board 300.It is these positions which correspond to the pin positions on theexternal enclosure. Likewise, during removal operations, the other edgesof arms 421 a and 421 b press against horizontally mounted external pinsfound in slots 435 a and 435 b, respectively. These slots are present inbase support member 320. However, the pins which lie in these slots arein fact part of the enclosing apparatus or the frame into which thecircuit board assembly is inserted. In this way, through a “reverse backstroke” operation, the entire board assembly is easily removed from thesystem into which it is connected.

FIG. 11 is also useful for illustrating part of the EMI shielding systemof the present invention. In particular, FIG. 11 shows the inclusion ofEMI spring shield 500 which is shaped to be readily inserted intoapertures 331 and 332 in stiffener 330. In particular, aperture 331includes a forward edge which engages a forwardly facing slot or pocket(reference numeral 502 in FIG. 13B). Accordingly, shield 500 includes anedge which is in firm electrical contact with stiffener 300. The otheredge of shield 500 includes a flexible portion 501 which extends throughaperture 332. The leading edge portion of shield spring 500 includespeak 504 which electrically contacts bezel 130 during cartridgeinsertion (see FIG. 12A). FIG. 12A illustrates the insertion an edge ofaperture 331 into slot or pocket 502 in spring shield 500. FIG. 12A alsoillustrates the presence of printed circuit card shield plate 202 in itsfully downward position extending through aperture 133 in bezel 130. Indoing so, tab 203 on plate 202 also electrically engages a portion ofshield spring 500. In particular, tab 203 engages edge 507 seen in FIG.13A.

FIGS. 13A and 13B provide a detailed description of the structure of EMIshield spring 500. This spring shield preferably comprises a singlesheet of stamped metal which is formed as shown. Preferable materialsfor this shield spring include beryllium copper ½ hard with an alternateof stainless steel ½ hard. FIG. 13A provides a top view of the desiredstructure, and FIG. 13B provides an end view. There are apertures inspring shield 500 between edges 505 and 507. It is through theseapertures that tab 203 is disposed so as to contact edge 507. Region 509is a tab region of the structure as is region 501. Top or peak 504engages the bottom portion of bezel 130. Also of note is the presence ofpocket or slot 502 which engages an edge of aperture 331 in stiffener330. In particular, it is noted that as stamped shield 500 preferablyincludes prongs 503 which are formed by the stamping operation employedin the manufacture of the shield spring. Prong 503 is also employed toprovide improved electrical contact between shield 500 and stiffener330. It is further noted that FIG. 13B is particularly useful in that itidentifies a plurality of surfaces or edges that are also visible inFIG. 13A. Correspondingly numbered parts are shown in these two figures.

From the above, it is seen that the present application describes aninterrelated system of structures and devices all of which are aimed atproviding tightly packed, dense, well-shielded printed circuit board andcartridge structures which renders it possible to insert and removeentire printed circuit boards even when fully populated by printedcircuit cards. In particular, it is seen that the printed circuit cardcartridges of the present invention provide a cooperative housing andinsertion structure for board level guides and which also incorporate anintegrated EMI shield system which is fully operative before, during,and after card insertion. It is further seen that the system of thepresent invention includes a relatively stiff printed circuit boardwhich is capable of sustaining insertion and removal forces even whenfully populated with electronic printed circuit card components.

It is also seen that the present invention includes structures whichprovide continuous EMI shielding which mates with and matches shieldingfrom a printed circuit card to corresponding EMI shield structures foundon the printed circuit board itself. It is also seen that the cartridgepreferably employed in the present invention includes pivotably mountedcomponents which make printed circuit card insertion relatively easy.Lastly, but not limited hereto, it is seen that the system and apparatusdescribed in the present application fulfills, either individually orcollectively, in its various embodiments, all of the objectives setforth above though not necessarily all of them simultaneously.

While the invention has been described in detail herein in accordancewith certain preferred embodiments thereof, many modifications andchanges therein may be effected by those skilled in the art.Accordingly, it is intended by the appended claims to cover all suchmodifications and changes as fall within the true spirit and scope ofthe invention.

What is claimed is:
 1. A device, for receiving cartridges which includeelectronic circuit cards with edge connectors, said device comprising: aprinted circuit board; a plurality of guides mounted on said circuitboard and disposed in substantially parallel rows with the guides ineach row including at least one substantially horizontal slot whichaligns with other substantially horizontal slots in other guides withinthe same row to deter vertical motion of said cartridge upon insertion;and connectors for receiving electronic circuit card edge connectors,said connectors being disposed on said printed circuit board betweensaid rows of guides.
 2. The circuit board of claim 1 in which saidguides in each row also include at least one substantially vertical slotwhich aligns with other substantially vertical slots in other guideswithin the same row to deter horizontal motion of said cartridge.
 3. Thecircuit board of claim 1 in which said guides comprise an electricallynonconductive material.
 4. The circuit board of claim 1 in which saidguides comprise a polymeric material.
 5. The circuit board of claim 1 inwhich said plurality of guides comprise an integral structure.
 6. Thecircuit board of claim 1 further including a board stiffening member. 7.The circuit board of claim 6 in which said stiffening member includes atleast one aperture therein for mounting said guides to said board.
 8. Adevice, for receiving cartridges which include electronic circuit cardswith edge connectors, said device comprising: a printed circuit board; aplurality of guides mounted on said circuit board and disposed in asingle row with the guides in said row including at least onesubstantially horizontal slot which aligns with other substantiallyhorizontal slots in other guides within said row to deter verticalmotion of said cartridge upon insertion of said edge connector and withthe guides also including at least one substantially vertical slot whichaligns with other substantially vertical slots in other guides withinsaid row to deter horizontal motion of said cartridge; and connectorsfor receiving electronic circuit card edge connectors, said connectorsbeing disposed on said printed circuit board between said rows ofguides.
 9. A device, for receiving cartridges which include electroniccircuit cards with edge connectors, said device comprising: a printedcircuit board; a plurality of guides mounted on said circuit board anddisposed in parallel rows with the guide in each row including at leastone substantially horizontal slot to deter vertical motion of saidcartridge upon insertion; and connectors for receiving electroniccircuit card edge connectors, said connectors being disposed on saidprinted circuit board between said rows of guides.